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    <script>
        var max = (arr, fn = (a, b) => a > b ? a : b) => {
            var max = arr[0];
            for (let i = 1; i < arr.length; i++) {
                max = fn(max, arr[i])
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            return max;
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        var maxNum = max([1, 2, 3, 4, 5])
        console.log(maxNum);
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